A conventional system or device for displaying an image, such as a television monitor, projector, or other imaging system, is frequently used to display a still or video image. Viewers evaluate display systems based on many criteria such as image size, contrast ratio, color purity, brightness, pixel color accuracy, and resolution. Image brightness, pixel color accuracy, and resolution are particularly important metrics in many display markets because the available brightness, pixel color accuracy, and resolution can limit the size of a displayed image and control how well the image can be seen in venues having high levels of ambient light.
Many digital display systems create an image with one or more modulator panels. In particular, modulator panels modulate light that is incident thereon to form an image or sub-image. Multiple modulator panels may be used to create a higher quality image. In such systems, multiple components, such as beam splitters, total internal reflection prisms, and color combiners, to name a few, are used to direct light to and from each of the modulator panels. The number of such components present frequently increases as the number of modulator panels increases. As light is directed to each of these components, a small portion of the light diverges from the intended path. If this light, referred to as stray light, reaches the screen it mixes with the modulated light. The mixing of the stray light with the modulated light reduces the contrast of the displayed image.
In addition to transmitting some amount of stray light, the presence of multiple components frequently constrains the back focal distance of the display optics. In particular, the location of the display optics is frequently selected to accommodate other components while remaining in communication with the modulator panel or panels.